Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Loss Contingencies [Line Items]
Commitments to extend credit to commercial customers	$ 12,600,000	$ 12,700,000
Maximum credit risk for recourse associated with loans sold under Federal National Mortgage Association Delegated Underwriting and Servicing program	4,300,000	4,200,000
Loss contingency accrual	133,000	$ 157,000
Minimum
Loss Contingencies [Line Items]
Range of reasonably possible losses	0
Maximum
Loss Contingencies [Line Items]
Range of reasonably possible losses	$ 25,000